Metro officials point to a backlog of maintenance issues as the cause of a surge in problems on the line between Long Beach and L.A., which carries 26 million riders per year.

As officials build mass transit lines at a rapid clip, Los Angeles County's oldest and most-used light-rail system has been breaking down with alarming frequency.

The Blue Line from Long Beach to downtown L.A. — one of the nation's busiest light-rail routes, with 26 million annual riders — has suffered a rash of maintenance problems that have left commuters who rely on the service facing major delays.

In January and February, Blue Line trips were late or canceled 858 times — roughly 14 times a day — compared with 428 times during the first two months of 2011. The situation began to improve in March, but on the 26th, riders suffered through several hours of delays because of damaged overhead power lines.

"I've traveled many metro lines in the nation, and I've never experienced so many delays and breakdowns as I have on the Blue Line," said Robert Cheshier of Long Beach, who rides the train three days a week to his job in downtown Los Angeles. "Seriously, who is overseeing this poorly run transit system?"

The county's first commuter rail system built since the Pacific Electric Red Cars, the 22-year-old Blue Line has seen at least $239 million in maintenance put off over the last decade. The amount represents only part of a $1.3-billion maintenance backlog that hangs over the entire rail and bus network run by the L.A. County Metropolitan Transportation Authority.

Although most of the work elsewhere involves service vehicles, stations and other facilities, the Blue Line's to-do list targets more critical elements such as tracks, signals and passenger cars.

The problems threaten to become a liability for Metro, which is trying to convince car-loving commuters that the transit system offers a reliable alternative to driving.

Some officials said that in the effort to build new rail lines, Metro did not focus sufficient resources on maintenance.

"The Metro Board and staff who were in charge weren't paying close enough attention to the ongoing day-to-day," said board member Richard Katz. "Routine maintenance is not as interesting as a new shiny object, and maintenance gets overlooked."

Metro officials acknowledge that the line has maintenance problems, and the agency is trying to address them. By 2020, they plan to put $558 million into improving the system's reliability, including $203 million for new replacement cars.

"We need to start trying to catch up with that deferred maintenance," said Metro Chief Executive Art Leahy, who replaced longtime agency head Roger Snoble in 2009. "Some of it has been deferred so long that it doesn't matter at a certain point because you just retire the piece of equipment."

Officials say the agency-wide backlog has yet to cause significant service disruptions across the rest of the transit system.

They note that the bus fleet as well as the Green Line and Gold Line light-rail systems have newer vehicles, but that is no assurance that the growing amount of deferred maintenance won't lead to service problems and more expensive repairs in the future.

As for the Blue Line, they pointed out a drop in delays and canceled trains for the first weeks of April.

"I believe January and February were aberrations," Leahy said.

Passenger fares only cover a fraction of the operating and maintenance costs. And though Metro appears to be flush with billions of dollars in sales tax revenue from transportation-related ballot measures, the money is primarily earmarked for new highway and transit projects.

Either under construction or in the planning stages are the Expo Line to the Westside, the Foothill extension of the Gold Line in the San Gabriel Valley, the Westside subway extension and the Crenshaw Line to South Los Angeles and Inglewood.

Normally, it takes about 55 minutes for trains to go from Long Beach to L.A. through Compton, Watts, and South-Central L.A.. But MTA statistics show that the average daily delay in January was 34 minutes, in February 37 minutes and at the beginning of March 22 minutes. In December 2011 the average delay was 13 minutes.

Metro officials also say that the number of miles Blue Line cars travel before breakdowns has declined from about 26,000 miles in 2008 to about 19,500 miles last year. The line's cars, which have a service life of 30 years, are now more than 20 years old.

More than a quarter of the service disruptions in January and February — the largest portion — were related to maintenance issues, according to Metro. Officials said the other delays were attributed to accidents, operational problems, construction of the Expo Line and a power system failure Feb. 23 that led to delays of up to two hours for commuters during the morning rush hour.

Also contributing to the Blue Line problems have been stalled rail car purchases and shortages of state funds to pay for transit operations and maintenance.